Decorated foil and film



Patented Feb. 17, 1942 DECORATED FOIL AND FILM Kurt Feuerstein,Frankfort-on-the-Main, Germany, assignor to Riihm Philadelphia, Pa.

No Drawing.

2 Claims.

This invention relates to a process of preparing decorated films, foil,and sheets of thermoplastic materials. It relates more partic ifarly toa process of applying designs in various colors to sheets ofthermoplastic material by forming the sheet on a non-absorbent surfacein which the design has been etched or engraved, the coloring materialhaving been placed in the depressions of the engraving or etching priorto the formation of the plastic sheet.

' It has been proposed to make decorated, molded articles fromhardenable, artificial resins by applying to the walls of a mold, whichmay or may not have a design engraved thereon, a color paste in whichthe vehicle is a solution of the artificial resin, evaporating thesolvent, filling the mold with a molding powder, and forming andhardening thearticle under heat and pressure as is commonly done in themolding industry.

The present invention contemplates a process for decorating films orsheets of thermoplastic material, according to which the design isengraved, etched or carved on a plate of suitable material such asglass, metal or insoluble, heathardened resin, and the depressions ofsuch design filled with a paste of color or pigment in a non-dryingvehicle. A solution of a thermoplastic substance in a suitable solventis then poured over the plate to a depth depending on the thicknessdesired in the final sheet and the concentration of the solution, afterwhich the solvent is evaporated and the dried sheet removed from theplate. By this method the pigments and vehicle are transferred to thethermoplastic sheet and are removed with it from the plate withoutdistorting even the finest lines in the design.

The plates on which the design is carried are not subjected to any verygreat mechanical strain and can. therefore, be made of glassylight,easily worked metal such as copper, brass, aluminum, etc.; or of anartificial resin which is insoluble in and unaffected by the solution ofthermoplastic material. Porous materials such as wood may also be usedwhen the surface is provided with an impervious, insoluble layer ofmaterial in which the design my be cut.

The design may be imparted to the surface of the plate in any desiredmanner as by etching, engraving, carving, or stamping. The design itselfmay be writing, drawing, picture, or an ornamental design.

The color pastes which are employed to fill the depressions of thedesign may be made of any pigment, white, black, luminous or coloredwhich & Haas Company,

Application May 17, 1939, Serial In Germany June 4, 1938 is insoluble inany of the liquids employed. Color lakes may be used, provided thedyestufl is insoluble. On account of their greater fastness to light,inorganic pigments are preferred. Diiferent colors can, of course, beapplied to diiferent parts of the design to secure any desired effects.The thermoplastic material may also be uniformly colored in addition tothe colors in the design by means of soluble dyes or insoluble colors.

The vehicle used in preparing the pigment paste should be non-drying orslow drying. Oils, high boiling liquids commonly used as plasticizers inthermoplastics, and high boiling solvents which are soluble in thecommon organic solvents may be employed. Low boiling liquids usuallyevaporate too rapidly and are not suitable. Furthermore; the vehicleshould have a fairly high viscosity. The paste may be applied bycovering the plate and wiping off all except that in the depression.When different colored pastes are used on the same plate, it may beadvantageous to apply them only in the proper depressions of the design.

The film-forming materials which are suitable are the plastic materialssoluble in organic solvents, particularly the thermoplastics. Examplesof such materials are polymers, co-polymers, or mixed polymers of vinyl,acrylic and methacrylic compounds such as the polyvinyl esters, thepolyacrylic and methacrylic esters, polystyrene, polyvinyl carbazol.Cellulose ethers and esters may also be employed, for example cellulosenitrate. Particularly suitable are polyvinyl acetate, polymethylmethacrylate and polyethyl methacrylate. Plasticizers may also beemployed with any of the thermoplastics as wellas inert fillers. It isthus possible to obtain hard, stiff sheets or soft, flexible foilsdepending on the composition of the thermoplastic material used. Thefilms or sheets may be subsequently bent or shaped in any desiredmanner.

Since the vehicle employed-in making the pigment paste is more or lesssoluble in the solution of thermoplastic, the latter penetrates thepaste and displaces the vehicle. It thus surrounds the pigment particleswhich are then embedded in the finished sheet a short distance below thesurface so that the design cannot be rubbed off. A single plate can beused for the production of a large number of decorated sheets, each oneof which will have the design reproduced on it in the finest detail.

In the manufacture of plain films by pouring a solution of plastic on asuitable base and the film is removed from the plate.

evaporating the solvent, it is common practice to put a thin film of oilon the base or to dust it with tale to reduce adhesion. The tale is useddry and the base on which it is spread has no depressions. According tothe present invention, it i necessary to wet the pigment with thevehicle before application as, otherwise, the pigment cannot be properlyretained in the depression when the solution of thermoplastic is pouredon the plate. It is only by using a pigment thoroughly wet with thevehicle that an exact reproduction of the color design in thethermoplastic is possible.

The invention may be illustrated by the following examples but it is notlimited to the exact thermoplastic, pigment, binder, etc. shown as itmay be otherwise practised within the scope of the appended claims.

Example 1 A glass plate on which an ornamental design has been etched isrubbed over with a pigment Example 2 The depressions of a desi nengraved on a copper plate are filled with a pigment paste such as thatused in Example 1. A solution of polystyrol in benzol is poured over theplate and the solvent evaporated. A hard sheet having the designembedded in it is obtained on removal from the copper plate.

Example 3 A paste of gold bronze in dibutyl phthalate is applied asdescribed in Example 1 to a design etched on glass. A solution ofCelluloid containing a black pigment is poured on the plate and thesolvent evaporated. The dried film shows a gold design on a blackbackground similar to the so-called Japanese lacquered articles.

Films obtained according to the process described may be used alone fordecorative purposes or they may be mounted on a backing of leather,wood, fabric or paper for use in interior decorating, furniture, lampshades, pocket books, mirrors, brushbacks, and other fancy articles.Very thin foil may be decorated by the process disclosed herein and usedas a wrapping material.

Other vehicles for the pigment may be used, such as non-drying orsemi-drying oils, other esters of phthalic and other dibasic organicacids, triaryl phosphates, etc. The main characteristic of the vehicleis that it should be soluble in the solvent used for the plastic andcompatible with the latter.

I claim:

1. The process of applying designs to sheets of thermoplastic materialwhich comprises filling the depressions of a design sunk in a non-porousplate with a paste consisting of a pigment and an organic vehicle,pouring a solution of a thermoplastic material on said plate, saidvehicle being soluble in said solution, and evaporating the solvent.

2. The process of applying designs to sheets of thermoplastic materialwhich comprises filling the depressions of a design sunk in a non-porousplate with a paste consisting of a pigment and an organic vehicle,pouring a solution of a thermoplastic material comprising a polymerselected from the group consisting of the lower aliphatic esters ofacrylic and methacrylic acids on said plate, said vehicle being solublein said solution, and evaporating the solvent.

KURT FEUERSTEIN.

